A machine such as a construction or mining machine typically has a powertrain that includes the components that transmit and adjust the power or energy output from the prime mover, such as an internal combustion engine, to the point of utilization such as propelling the machine or operating implements associated with the machine. Powertrain components can include drive shafts, transmissions, differentials, power takeoffs, and other components that are responsible for operation of the machine. The prime mover is the source or origin of the kinetic or mechanical energy transmitted through these components. An internal combustion engine, for example, can combust a hydrocarbon-based fuel to convert the chemical energy therein to kinetic energy or mechanical power embodied as the rotational motion of a driveshaft. While traditional machines included a single prime mover as the source of energy, more recent hybrid designs may combine different technologies to provide complementary sources of energy for the machine in order to improve efficiency and prolong machine life.
One common hybrid technology is regenerative braking in which the powertrain is configured to slow or stop the motion of the machine, or the moving implements of the machine, by capturing and storing the kinetic energy associated with the motion. Regenerative braking can therefore recover some of the applied braking power of the machine for reuse rather than dissipating the power through friction and heat generation. In a hydraulic hybrid design, the captured energy can be stored in the form of pressurized fluid in an accumulator that can later be reapplied as kinetic energy in the powertrain. An alternative design for a hybrid powertrain is an electric hybrid system in which the captured energy is stored as electrical power in batteries or capacitors for further use such as to power electric motors associated with the machine. U.S. Pat. No. 7,565,801 describes a machine, such as an excavator, which includes variations of a hydraulic hybrid system and an electric hybrid system to capture and reuse kinetic energy associated the operation of the excavator. The present disclosure is similarly directed to recovering and reusing the energy transmitted through one or more powertrains associated with a machine such as an excavator.